Help With 600 Sci !!
 

Need Help With Merc 600 Sci's . I'm Having Trouble Running My Engines Above 4700 Rpm. The Smart Craft Race View Is Putting The Engines In Guardian Mode Do To A Charge Temperature Overheat. I Have Checked My Strainers And They Are Clean. There Is Plenty Of Water Pressure According To The The Race View .there Is 35 And 37 Psi At 4700 Rpm. All Other Parameters Check Out Fine Except The Blown Air Temp. Any Ideas ??

Re: Help With 600 Sci !!
 

As you say, its the intake charge temp that is too high. You might need to get some more fresh air into engine compartment to feed them.

Whats the outside air temp????

Re: Help With 600 Sci !!
 

My Boat Has Two Large Scoops One To Each Side. Outside Temp Is In The Low 90's . Its Miami So It Is Always Hot. I Do Not Think It Is The Air Going To The Blower. It Is The Air Boosted After The Charger On The Way To The Manifold.

Re: Help With 600 Sci !!
 

I have only looked at these engines at the Miami boat show so I'm not an expert, but some thoughts anyway.

You need to confirm that water is flowing through the intercooler. Locate the intercooler outlet line where (I believe) it dumps into one of the tailpipes. Disconnect it and plumb extra line where you can see it dumping overboard. I think the intercooler is fed by the sea water pump so when you start the engine you should see water flow. If the intercooler is fed by a seperate pickup the boat will have to be on plane to see much water flow. This test will tell you if you have a blocked intercooler.

I don't know but maybe it's possible for stuff small enough to get through the strainer to be big enough to still block the small water passages in the intercooler. The water flow through the intercooler possibly helps relieve block pressure. Isn't 35 to 37 psi on the high side? Also suggests the intercooler is plugged?

Good luck

Mercury 600 sci problems
 

I have a 600 sci with problems. They always seem to point to low water pressure or hi intake charge temperature. I have spoken with four other 600 owners with the same problem. Does anyone have any words of advice? I replumbed the 600 with a bottom pickup for the motor/sea pump and I have the vertical holes in the XR all blocked with the front nosecone holes feeding just the intercooler. I changed the exit of the intercooler to dump overboard instead of back into the headers. I was getting hot exhaust gases back towards the intercooler with the "stock setup" . The boat will run great for a brief time but most of the time will not run past 4600 rpm. I am running a teague strainer (small). I know that this problem exists for many merc 600 sci owners. Any solutions? I have tried changing sensors but they are the same. Scan tool says low water pressure. There are no blockages in the system. I am going to try taking the strainer off line to see if that is the answer.

Had the same problem with my 42PR....I would back flush the intercooler and the oil cooler as there is probably debris stuck in the which is inhibiting water flow. This will inhibit the performance of the intercooler and you will get the "chrg air temp" code and ultimately "guardian mode" if you stay into the throttle. Trust me....been there, done that!! Drove me crazy for a few days as the guardian mode would come on immediately after the CHRG AIR code which led me to believe I was hitting the limiter prematurely. Ended up being a bunch of seaweed stuck in the intercooler and oilcooler which caused the problem.

Both go hand and hand. Not enough water, you get high IC discharge temps. I feel water psi needs to be at least 25psi whatever way possible. 28-30 is where th stock system goes into reduced power mode.

Listen to what DC said. I have no doubt you have debris or a block in the IC core or the oil cooler. I have a few things that will help this as well. Some water routing changes that will really help. Standard strainers do not filter the debris properly for the small water passages.

The mechanic is working on my boat again. I will have an update tomorrow.

The mechanic has run the intercooler to the outdrive nosecone only. The intake chrg temperature is good now. The problem is the water pressure. It is in the high twenties. I need to get it into the mid thirties. I have a through hull bottom pickup intstalled that is aggressive. He has bypassed the sea strainer to see if that helped. It did not. The oil cooler is clean and no passages are blocked. Everything has been backflushed numerous times. I guess it's back to the drawing board!

I would contact Dustin directly... He has answers.

Chris

Thanks guys, today the mechanic switched the pickup from the nosecone to feed the motor directly. It picks up water from the four front holes and three bottom holes on the vertical sides. All others are plugged. The intercooler is being supplied from the external bottom through hull pickup. Both are run through strainers. This seems to be working. I have worked with Dustin on the phone and he has been very helpful. I have not done final testing with my boat but after his remap I have gained 5mph. The boat is a Howard Deck with a Mercury 600 sci. I don't have it loaded lightly. It has two batteries and a large stinger battery, two amps, subs, ice chests, two anchors, toys, and a bunch of other crap on the boat. The boat runs 87mph with a bravo 30 non labbed. 86 mph with a 28 labbed maximus five blade. I think it would run faster with 32 labbed. I don't think I will ever try it though...I have also added some additional resistance by adding the bottom pickup and I have oversized the four holes on the drive slightly to try and pick up more water. My mechanic says the boat is running in the mid 30s for water pressure now. Hopefully these intermittent warnings and guardian modes times are now over. Dustin, thanks for your help with my problem and the welcome addition of more power! I notice alot more torque than before.

Bingo-
 

Agree- sounds like a clogged intercooler.

The charge temp air warning indicates a potential detonation condition and the 600sci will severely retard the the timing to keep your pistons alive.

Id say that what you need is a "sand strainer" on the inlet side of the intercooler.

Flush it out or if this is all is beyond me I assume you replaced the impeller already and inspected the water pump housing.

good luck-

Uncle Dave

Laveycraft 2750 Ilmor-710
Laveycraft 20.8 Sebring 406 SB
Fleetwood nitrous toy hauler
Yamaha raptor 700/Kawi KFX 450
Nissan Titan

Hope its fixed for good- !!

Id still get a sand strainer.

Uncle Dave

Laveycraft 2750 Ilmor-710
Laveycraft 20.8 Sebring 406 SB
Fleetwood nitrous toy hauler
Yamaha raptor 700/Kawi KFX 450
Nissan Titan

Dustin,

Does the power reduction mode start before or after the Guardian mode kicks in and slows the motor way down?? Ie, if the motor is not getting over 28-30psi, is the power gradually reduced? I feel that as I try to trim my IMCO SC drive out, much past parallel with the plane of the keel, that there is a sensation that as I give the motor more throttle.... nothing happens. I can give the motor full throttle or 3/4 throttle, and boat speed remains the same at about 5100 rpm. If I trim too far, it kicks into guardian mode, lights start flashing, buzzers start beeping, and it feels like the motor goes to half power.

Chris

I am looking into a sand strainer. The boat is running well. I appreciate all of the advice.

ttt ^ Dustin?

No, it activates the rev limit control and the buzzer beeps. Certainly going into reduced power when your hearing buzzer, which is directly related to water psi.

Dustin,

Thanks for the reply, and the considerable time you spent with me on the phone.

YOU ROCK!! :Score-101010:

Chris

Dustin,

Thank you for the time you spent with me also on the phone. And thanks for the reprogram. I am certain to enjoy the extra 4 mph and increased torque. I am taking the boat out this weekend for some wringing out.

Your description of the throttle response at top end is exactly my experience, too! I came from a 525EFi, and was used to arelatively linear increase in power and speed in relation to throttle position and rpm. The 600 doesn´t like to run at high rpms, or the system ist cutting the power at top end. I´ve tried many different props and still feel that something is holding back.
The water pressure on my settup is low, but will get into the low 30´s if I don´t trim my Imco lower up too high. I have only had one Guardian mode in 50 hours (accelerating, as the prop cavitated the boat speed was low, the water pressure was the error code).
I´m starting to think that the ECU could be cutting power at top end, causing the last third of the throttle movement to have little or no effect.

Thanks Dustin.
No power reduction without a buzzer, then?

Some early 600sci's could reduce power due to high IAT2 temps but it still cut the rev limiter, but would not throw code. They control power by the boost bypass, but not during fail safe modes, thats always done with engine misfiring/

Wild Card,

I feel you man.....

I think that Mercury is bypassing the boost at top end to only make 600hp. I believe that they are doing this so that they are not competing with the 700sci, which they charge a lot more money for. I am hoping that Dustin's ECM upgrade is the answer.

Chris

That´s exactly what it feels like!
After running a 496HO, the 525 was a revelation! Big power increase, and the motor made it very clear if it liked the prop it was pushing. The 600 is more like the 496, as far as not really wanting to use it´s rev range until you prop down that the speed is out of reach. longer props draw more torque out of the motoras the blower lights up, but the power tails off at 5100. Mid range pull is sharp, and the boat doesn´t mind being loaded up with a few extra passengers and full tank, but the liveliness of 525 isn´t there.
Keep me posted on the ECM upgrade!

Wild Card,

I agree.... 5100 is where my poops out also. Even with a variety of props. The speed seems to be always about the same on the top end. When I propped it to spin about 5350, with a Hydromotive 27 pitch P5x, the snappiness of the midrange is awsome, at the expense of a couple of mph on top.

I will let you know about the ECM.

Chris

Hello all,

I hope my problems with the 600 sci are finally over. Based on my talking to many 600 owners all with the same problem of the boats cutting out over 4600 rpm's. Mercury is aware of these problems but they ignore them hoping they will go away. I spent my whole summer and alot of money chasing these problems. Mercury's stock setup with the water feeding the motor and intercooler from the outdrive only is less than adequate. I think the problem was solved by feeding the intercooler with a separate bottom pickup and isolating the outdrive to feed the motor only. I plugged the top vertical holes in the outdrive leaving only the three bottom ones open. I slightly drilled out the nosecone holes. The result is the end to the constant beeping, engine cutting out and Mercury problems that they can't fix. The motor is finally running well.

I will be testing this weekend and posting results. If you have problems with your 600 let's talk.

My guess is that both Wild's and my outdrive lowers are IMCO's, which are notorious for producing lots of water pressure and volume. my only gripes with the 600 are its lack of power on the top end because of Mercury's bypassing of the boost in order to sell 700's, and the low water pressure issue if I over-trim the outdrive much past the horizontal plane of the keel of the boat. If I trim up too much, the nose of the IMCO shadow's the water inlet causing pressure to drop and the motor goes into Guardian mode. This always seems to happen at about 5100 rpm when I am trimming up to get those last couple of mph on my boat. I have found some relief in Hydromotives P5x prop which gives me a lot of bow lift and reduced slip. Because of this, I don't have to trim up as much to see max speed, and the water pressure issue is mostly resolved.

Chris

Chris,

I had another customer that had a similar issue with the imco. One thing that helped was opening the hole towards the top of the current one, since the hole is going away when you trim the outdrive. This will really help in the high trim application.

Thanks

This is certainly the best case scenario. There is simply not enough water supply for the engine and intercooler through the outdrive on most applications. If your going 120+mph, no problem, but 600 and 700 can't typically get you there. Other than idle water flow, the seperate pickup creates far more flow. Were also coming out with some IC upgrades that have to do with the water flow, and this will also improve performance. A good strainer is needed to keep it very reliable. CP makes a nice IC strainer.

Let me know how testing goes! :ernaehrung004:

Great 600 thread, back to the top.

I too had 1 engine this past weekend that would not go past 4100-4200 rpms, I think I already have some of Whipple's 600SCI upgrades, I just need to talk with Dustin, and I also have to get the PCM Serial #'s and have Dustin check to see if they have been reprogrammed. I have the external IC dump, but no dedicated external pick-up. I will have to check my H2O pressures when out next time, but they have to be in the 30's, but at what RPM?
Thanks,
Dean

Dustin will know the specifics on water pressure. Were you gettting a 2 beep alarm?

R,
No alarm that I could hear. Also, when I was flushing that motor later that day, after about 3-4 minutes running @ idle, I looked down, and all the gauges for the engine were JUMPING all over the place! I shut her down, waited 10 seconds, and fired her back up and everything was good, and I finished the flush w/o a problem? I'm thinking I might have a grounding issue with the gauges, but I will talk with Dustin about it also. I have already sent him an email:drink:
Thanks,
Dean

I think this is repaired by using a resistor somewhere. Check with Dustin.. I seem to remember having the same problem

R,
Thanks for more great 600sci inside info, I plan to trying to talk with Dustin this afternoon.
Thanks again,
Dean

Talked with Dustin today, he's very helpful and knowledgable guy. He gave me a few ideas to look this weekend if it doesn't RAIN!
Thanks Dustin,
Dean

Help with 600sci
 

Are you running dual sea strainers one for the drive and 1 for the low water pickup?

600 sci
 

Can anyone be of help ? I’ve had my Howard 28 SDS for 5-6 years.. It has a stage 2 whipple upgrade. Everything has been perfect and I’ve just had to have it serviced annually. Over the last couple of months I keep having a guardian alarm w a continuous beep. Normally it’s mid throttle around 80 mph.. The boat repair place said its a charge temperature overheat code. Can anyone that’s maybe had this issue help. Thank you.

To get the best help start a new thread, it seems people see old threads and sort of dismiss them.
I question your "boat place" if they tell you what code it has but can't diagnose or fix the issue.
Unless maybe you didn't want them to.